'Looper:' Playing a younger Willis

Mark Olsen, Special to the Los Angeles Times

In "Looper," Joseph Gordon-Levitt plays a hitman in the near future whose targets have been sent back in time; one day, the man who turns up turns out to be an older version of the assassin. To bring the premise to life, Gordon-Levitt had to look (and act) like Bruce Willis, who plays the older incarnation of his character, and that meant spending three hours a day in the makeup chair.

"That was really scary because you commit to that and there's no real way out of it," said "Looper" writer-director Rian Johnson of using practical prosthetics to make one actor look more like the other. "But the biggest thing is Joe's performance, he's really doing Bruce in a big and daring way, but he strikes a balance between obviously imitating Bruce and also building this organic performance."

Johnson's two previous features were playful, smartly knowing takes on familiar genres — he mashed up teen movies and film noir in "Brick" and caper films with a romance in "The Brothers Bloom." So it makes sense Johnson should now take on science fiction, which he referred to as "the tea-kettle cozy of genres, in that it slips over other genres."

As for the mechanics of manipulating the space-time continuum, Johnson admitted, "Time travel just never makes sense."

He added, "If you just tell somebody the plot, you're inevitably telling them the time travel stuff, but the movie actually uses that as a set-up. The best parallel I can draw is to the first 'Terminator' movie where time travel is used to set up this impossible situation between these people and then that situation plays itself out."